This is a prospective randomized double-blinded study that will compare two commonly used approaches for the continuous blockade of the brachial plexus: the CCPVB, which focusses on the six cervical nerve root (C6 root), and CISB, which focuses on the upper trunk of the brachial plexus. Data of sensory testing, motor strength, shoulder pain, phrenic nerve function, recurrent laryngeal nerve (RNL) function, ipsilateral Horner's syndrome, block time and medication doses used for block placement, will be collected. All observations and measurements will be made by a member of the research team who is unaware of patient allocation to any particular group.